1. Field of the Invention
The present invention relates to a casing structure for packaging a small-sized PC card, which is commonly called xe2x80x9cCompact Flash Cardxe2x80x9d (hereinafter referred to as xe2x80x9cCF cardxe2x80x9d), and is used in a mobile personal computer, portable telephone, digital camera and any surrounding electric/electronic device therefor.
2. Description of Related Art
A conventional CF card casing structure is disclosed in U.S. Pat. No. 5,397,857. Referring to FIG. 9, the conventional CF card casing structure comprises upper and lower insert-molded plates each having a metal sheet circumferentially embedded in its resin-molded frame. A chip-carrier substrate and an associated electric connector are sandwiched between the upper and lower insert-molded plates, and their resin-molded frames are super-sonic welded to form an integral package.
The upper and lower plates when subjected to the supersonic welding are liable to be deviated from their alignment position. The chip-carrier substrate has SMT leads soldered to its selected conductors, but such SMT leads when subjected to supersonic vibration are likely to come off. These will lead to poor yield of final products. The supersonic welding makes it difficult to take chip-carrier substrates off from defective packages for reuse. Even though the chip-carrier substrates are removed from such defective packages for reuse, the remaining casings cannot be reused, and therefore, new cover plates are required. The manufacturing cost of extra or additional cover plates is relatively high. Also disadvantageously, the chip-carrier substrates and I/O connectors when removed from the defective packages, are likely to be damaged more or less, and the cost involved for fixing such defective chip-carrier substrates for reuse is relatively high.
One object of the present invention is to provide an improved CF card casing structure which is free of such defects or problems as described above.
To attain this object a CF card casing structure comprising at least a cover plate having a metal sheet surrounded by and fixed to an insert-molded frame, a counter cover plate of metal sheet and a receptacle connector is improved according to the present invention in that: the insert-molded frame has a plurality of catch slots made therein; and the counter cover plate has a corresponding plurality of serrated latch pieces integrally connected thereto, each latch piece being adapted to be inserted into a corresponding catch slot for fastening the cover plate to the counter cover plate, thereby providing an integral assembly.
The fastening of the opposite (top and bottom) cover plates by inserting the serrated latch pieces of one of the opposite cover plates into the catch slots of the other assures that the opposite cover plates thus fastened are free of any deviation in alignment position, which would be caused for instance, in subjecting the top and bottom cover plates to the supersonic welding. Also, chip-carrier substrates and I/O connectors can be easily removed from defective packages without being damaged, leaving the cover plates free of any damages, too. Thus, such disassembled parts can be reused.
The cover plate and/or the counter cover plate may have an adhesive tape on its inside, the adhesive tape having adhesive partly applied to its carrier material, thereby permitting a sticky area to be left for fixing the receptacle connector, I/O connector and the like to selected areas of the cover plate by removing the carrier material. Thus, such parts can be fixedly attached to either cover plate with ease.
The opposite cover plates may be latched together to be mechanically and electrically connected, thus permitting the shielding of a chip-carrier PCB sandwiched therebetween.
The cover plate may have an insulating film applied to its inner metal surface, and likewise, the counter cover plate may have an insulating film applied to its inner metal surface, whereby the parts of the chip-carrier PCB sandwiched between the opposite cover plates may be protected from ESD voltage.